D10 is designed for a soft, wet, tacky track condition.
D20A is slightly tougher than the D10 and works well on crumbs or marbled tracks.
D30 is tougher than the D20A and performs well on cleaned off, dry-slick tracks.
RD40 is tougher than the D30 and is designed for harder, dry-slick tracks that begin to form a black groove.Indoor Surfaces:
The D20A will work well on cars that are easy on tires (i.e. Rookie, Jr. Honda) or on smooth indoor tracks that are not abrasive.
Because the D30 is slightly tougher than the D20A, it will be better on a wider spectrum of classes early in the indoor season.
Midway through the indoor season as the track gains grip and becomes more abrasive, it's recommended to switch to a Hoosier A35 NY1.

The 31.0/4.5-5 will measure approximately 31” on a 5x5 wheel at 8 psi. Compounds available in this size include D10, D20A, RD40, & A35. Please refer to the ‘Asphalt QM’ page for A35 compound applications.

The 32.0/4.5-5 SH will measure approximately 31.5” on a 5x5 wheel at 8 psi. Compounds available in this size include D20A & A35. Please refer to the ‘Asphalt QM’ page for A35 compound applications.

The 32.0/4.5-5 will measure approximately 32” on a 5x5 wheel at 8 psi. Compounds available in this size include D10, D20A, RD40, & A35. Please refer to the ‘Asphalt QM’ page for A35 compound applications.

The 4.5/10.0-5 will measure approximately 31 ¾ on a 5x5 wheel at 8 psi. This tire has a stiffer construction that provides more grip for higher powered classes that utilize a locked LR hub on their car. The compounds available include R60A (medium), and R60 (hard). The R60A is designed to work in the same conditions as the A35 NY1 compound. The R60 is designed to keep the car free on high heat, high traction surfaces. For further information, please visit the ‘Sprint/RR Kart’ page.

Recommended starting pressure is contingent upon track condition and compound selection.
The typical starting pressure on both dirt and indoor tracks is between 5-7 psi (cold) on the left side and 7-9 psi on the right side.

Every Hoosier race tire has a four character serial code embossed into ONE sidewall of the tire (example: J7B9). To be consistent when mounting from set to set, the tire should be placed on the rim so that the serial code faces towards the left side of the vehicle. This applies to tires without directional arrows. On tires with directional arrows, please mount the tire onto the rim so that the tire travels in the direction of the rotational arrow.

Once the tire is on the rim, we recommend placing the tire inside a mounting ring and adjusting the ring to fit snug around the tire. We highly advise using the mounting ring as we believe not using it can over stretch the carcass leading to inconsistent sizing. Never exceed 40 psi to seat beads. Once the tire has seated onto the rim, it is important the tire be initially stretched to about 10 psi over cold starting pressure to get the tire to its proper "profile". The tire should be set at this pressure for a few minutes and then dropped to the desired race pressure. The max inflation pressure is 57 psi (4.0 kg/cm2). Never exceed the max inflation pressure under any circumstance.